Roger,

Thanks for your comments. I was aware of most of the typical things
that manufacturers say. I have read the articles by Shell, etc. Whereas
they give good general operating rules, I don't think they have
addressed some of the issues that I brought up. I know that I would not
give out advice for what to do when you have to let an engine sit if I
were them. It is simply not smart to do so, since it is unnecessary.
Either use it or pickle it would be my advice. I do have a question for
you however. I noticed that you have posted about the fact that you run
your preheat 24/7 in the winter on your Deb, against the manufactures
suggestion. Several engine shops say that they can tell when someone
uses preheat all the time, as it corrodes the engine. You state that
Shell is even changing their position wrt this, and that you show good
results going against convention, as I have. Do you think they might
change their mind about ground runs? Also, what temp does the Tanis
keep your oil when you run it? Popular wisdom has it that it evaporates
water out of the oil and condenses it elsewhere in the engine causing
corrosion. If the wisdom that you have to get the oil up to 180 F is
true, then how do they explain preheaters evaporating water when they
don't get to near that temp? Just another of the contradicting things
that you hear.
Another thing I disagree on is that the oil is full of acids and
other crap that will eat away the engine if you coat the parts with it.
My engine would have been corroded to hell and back if this were true,
and it wasn't corroded when I tore it down last month. Who has ever
measured the corrosive ability of such an oil? If you have info please
share it. The main thing in the oil that necessitates changing it
regularly is pure and simple carbon particles that make the oil
slightly abrasive, sort of like a mild lapping compound. That is why it
turns black. Sulfuric acid is basically clear with a slight yellow
tinge. And as for "blow by", well, a good engine has little or no
blowby. An engine that does is not long for this world. Blowby will
totally destroy the oil layer on the cylinder wall and wear the engine
at a very high rate. It is the rings, which are spring loaded, and work
about as well (probably better since the layer of oil between them and
the cylinder wall is colder and thicker) that seal the combustion
gases that will show you this. If fire from combustion is blowing by
the rings, it will be very evident upon tear down or inspection, as
they will not have the polished face that is necessary. High crankcase
pressure is an indication of this, and no aircraft engine should be
allowed to deteriorate to such a level. Blowby of the rings is not
usually tolerable for any length of time, certainly in an aircraft
engine. Once it ever starts, it usually never stops because there is no
lubrication between the ring and cylinder and the rings and cylinder
wall wear very fast and their ability to "reseal" the cylinder is lost.
Sometimes, honing the cylinder, along with new rings, will restore it,
but a ruined cylinder is highly likely. Oh, let me tell you about some
of my experiences at the racetrack on this one.
Some other points..Lycoming use to recommend and may still, that
leaning to 50 deg rich of peak was the optimum place to operate. Braly
has proven to anyone with a brain that this is the absolute worst place
to operate for optimal engine life. And his approach of using proper
test procedures and just plain doing the research is what I like to
see. Just because the factories say something, is not proof that it is
true. Remember the Mobil AV-1 fiasco?
I am envious as hell of your Deb. I would love to rebuild one or
a old Bo some day when I'm retired. Congrats for such loving care of an
old masterpice.

Blue skies,
Rusty